The second baseman, who has missed 12 of the club's last 13 games with lower-back tightness, stood in the on-deck circle as the final out was made Thursday. Had the game been extended, Walker would have pinch-hit.

"We felt he was a usable player off the bench today," manager Clint Hurdle said. "We're optimistic he might be a little more than that tomorrow.

It seems possible, and perhaps even probable, that he'll be in the starting lineup Friday night, when Pittsburgh begins a three-game series against the Nationals.

Matt Slovin is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.